Evidence map›Paper›PMID 42286464›Full record

Trial reportBMC anesthesiology2026

Ultrasound versus nerve stimulation-guided interadductor approach for obturator nerve block: evaluation of injectate spread into the obturator canal in a randomized controlled trial.

Tetsuya Uchino, Masahiro Miura, Chihiro Shingu, Toshitaka Shin, Kenichiro Tomonari, Shigekiyo Matsumoto

Abstract readRandomized Controlled TrialComparative Study
In one paragraph

Trial report in BMC anesthesiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Tetsuya UchinoDepartment of Anesthesiology, Faculty of Medicine, Oita University, 1-1, Idaigaoka, Hazama-machi, Yufu, Oita, 879-5593, Japan.
Masahiro MiuraDepartment of Human Anatomy, Faculty of Medicine, Oita University, Oita, Japan.
Chihiro ShinguDepartment of Anesthesiology, Faculty of Medicine, Oita University, 1-1, Idaigaoka, Hazama-machi, Yufu, Oita, 879-5593, Japan.
Toshitaka ShinDepartment of Urology, Faculty of Medicine, Oita University, Oita, Japan.
Kenichiro TomonariOita Diagnostic Imaging Center, Oita, Japan.
Shigekiyo MatsumotoDepartment of Anesthesiology, Faculty of Medicine, Oita University, 1-1, Idaigaoka, Hazama-machi, Yufu, Oita, 879-5593, Japan. sigekiyo@oita-u.ac.jp.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThis study aimed to compare the percentage of local anesthetic spread into the obturator canal between the nerve stimulation-guided interadductor approach (NS-INTAD) and the ultrasound-guided interadductor approach (US-INTAD), and to evaluate anatomical factors influencing the effectiveness of the obturator nerve block (ONB).

methodsEighty patients scheduled for transurethral resection of bladder tumor were randomized to receive either NS-INTAD (n = 40) or US-INTAD (n = 40). In the lithotomy position, a mixture of local anesthetic and contrast medium was injected via the interadductor approach from the medial thigh. Injectate spread into the obturator canal was assessed by fluoroscopy, and the success rate and injection volume were compared between groups.

resultsEnhancement in the obturator canal was observed in 75% of patients in the NS-INTAD group and 90% in the US-INTAD group. Although the percentage was higher in the US-INTAD group, the difference was not statistically significant (P = 0.139). The volume of local anesthetic used did not differ significantly between groups (P = 0.07). In patients where the posterior branch of the obturator nerve coursed between obturator externus muscle fascicles, local anesthetic propagation into the obturator canal appeared limited.

conclusionThe percentage of injectate spread into the obturator canal tended to be higher with US-INTAD than with NS-INTAD. Our findings suggest that the lithotomy-position approach facilitates more cephalad local anesthetic spread than the supine-position approach. Furthermore, the development of the superior fascicle of the external obturator muscle appears to be an anatomical factor that inhibits injectate spread into the obturator canal.

trial registrationUMIN Clinical Trials Registry (UMIN-CTR) UMIN000027762; registered 15 June 2017.

Indexed as

Anesthetics, LocalNerve BlockObturator NerveUltrasonography, InterventionalAgedElectric StimulationFemaleHumansMaleMiddle AgedTransurethral Resection of BladderUrinary Bladder NeoplasmsAnesthetics, LocalInteradductor approachNerve stimulationObturator canalObturator nerve blockTUR-BTUltrasound guidance

Identifiers

PMID42286464
PMCPMC13483541

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.